Hey there, so I’m going to be telling everyone here how to access, work with, and communicate across universes.
First off, if you plan to start with this your first time around it would be wise to use explorer and carrier entities to help you out, without those you may have a problem navigating or bringing things across. Lake Trinity, Janus and his counterpart, The Abyss Walker, and my personal favorite, Cenonborga are good for it.
Now, as for what Alternate universes are, they can go from other lines to alternate interpretations of the lines we’re on right now. They allow you to reach from those that are the same except your sock is now red, to golden skies and silver air. From fictional universes to those never before seen by a human.
Our most “common” alternate universe entities are the shadow people, the versions of humanity so powerful and far apart from us at this point that the only way we can actually see them is as shadows.
In alternate universes also lie a variety of other versions of us from completely alien to basically us.
To contact them, you need to learn to reach across to their universes by using your own attention as a sort of bridge across the world. blank out your mind and observe everything around you without noting or labelling anything. Keep going until instead of words that you automatically read, all you see are just a bunch of black squiggles on a white background.
Once you can do that, start pushing your awareness and attention beyond the boundaries of what you perceive. Look at what’s BEHIND the words on the screen or the chair on the floor.
When everything you recognised turns into something utterly foreign and new, you’re ready to start using focused “raw” attention to push your awareness towards another universe. If you’re using this to contact an alternate universes humanity for example, intend with your attention to build a sort of bridge towards them, until you feel a sort of “click” sensation between you and them. From there you can communicate with them like any other entity from this universe, and if you want they can use you as a sort of foothold into this world to alter everything. Think Bill Cipher and Standford Pines if you want an example. Do the same thing except move yourself entirely into that universe if you want to do some Dimension Jumping. The two cups method they’re so fond of? Basically just another way to go about doing this.
As for why you would want to reach another universe? Basically any reason you can think of. You can change anything from the color of your pants to history to individual people however you want that way.
And as for why you would want to contact entities from other universes? Because oftentimes they have the ability to break this one in way’s that the more common entities could only dream of. And that’s not mentioning how quickly they can drive your evolution forwards if you reach out to the right ones. Shadow people anyone? Power lies at the edges of your perception.
Do this for awhile and you’ll notice reality breaking around you, people see you at places you’ve never been at the same time. You have memories of things you didn’t do in this reality, you can talk to alternate versions of yourself, things start moving around on their own for no reason, etc etc etc.